This invention relates to a body structure of a passenger car having a front wall arranged between the forward car section and the passenger compartment, and two lower mutually spaced forward side rails which are each connected to a floor support.
From European Patent Document EP 0 226 012 B1, a body structure of a passenger car is known which has a front wall arranged between the forward car section and the passenger compartment and has two mutually spaced side rails which are connected to floor supports which are situated behind them and which extend as an extension of the forward side rails. The body structure also comprises laterally exterior side members, a floor and upright hinge pillars. A rearward end section of the forward side rail is connected by way of a support element with the laterally exterior side member.
It is an object of the invention to further develop the body structure in the area of a front wall, which bounds the passenger compartment, in such a manner that, on the one hand, a stiff passenger compartment is created and, on the other hand, the forces occurring during a frontal impact are absorbed well and are introduced in a large-surface manner from the forward side rails into the adjoining body structure.
This object is achieved, at least in part, by providing body structure of a passenger car comprising:
a front wall arranged between the forward car section and a passenger compartment,
two lower mutually spaced forward side rails which are each connected to a floor support which is situated behind them and which extends as an extension of the side rail,
laterally exterior side members,
a floor, and
upright hinge pillars,
wherein the two lower forward side rails extend to the front wall and are connected in a force-transmitting manner with this front wall and with a first cross member fitted on an exterior side onto the front wall,
wherein a second cross member is arranged on the front wall at the level of the first cross member on a side facing the passenger compartment, said second cross member being connected in a center area of its transverse course with a tunnel reinforcement placed on a longitudinally extending transmission tunnel,
and wherein the second cross member, in its laterally exterior areas--viewed in a vertical direction--widens in a downward direction and is divided into two separate hollow rail sections, an upper one of the hollow rail sections being connected to the front wall, the wheel house wall and the hinge pillar, and a lower one of the hollow rail sections being connected with the front wall, the side member and the floor.
Advantages achieved by means of the invention are that, by means of the linking of the lower forward side rails to first and second front-wall-side cross-members, a favorable flow takes place of forces originating from the frontal impact because the forces are introduced from the height of the cross members into a lower support structure (front wall, floor, side member, hinge pillar) or into a reinforcing support of the transmission tunnel.
The absorption of force is positively influenced by the fact that end areas of the first transverse member facing the forward car project into the hollow space of the adjoining forward side rails and are connected to the front wall and a stiffening web plate arranged inside the side rail.
In especially preferred embodiments, the web plate, which extends downward in the direction of the floor support, extends to the front wall by means of its rearward edge and has the effect that, in the case of a crash impact, the forward side rails do not tilt away upwards. The forward side rails extend continuously to the first cross member fitted onto the front wall and are connected with it in a force-transmitting manner. A second transverse member which is arranged approximately at the same level on the side of the front wall facing the passenger compartment distributes the forces into the front wall, the wheel house walls, the side members, the upright hinge pillars and into a tunnel reinforcement placed on the transmission tunnel, whereby a stable passenger compartment is created. In lateral exterior areas, the second transverse member is divided into two hollow support sections which are connected to one another by a web-type connection area.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.